Mosquitoes find their victims in part by odor, so it makes sense to wonder whether what we eat and drink influences our attractiveness to mosquitoes. A study in West Africa (Lefèvre et al. 2010), working with the mosquito species that carry malaria, wondered whether drinking the local beer influenced attractiveness to mosquitoes.

They opened a container holding 50 mosquitoes next to each of 25 alcohol-free participants and measured the proportion of mosquitoes that left the container and flew toward the participants (they called this proportion the “activation”). They repeated this procedure 15 minutes after each of the same participants had consumed a liter of beer and measured the “change in activation” (after minus before). This procedure was also carried out on another 18 human participants who were given water instead of beer. The change in activation of mosquitoes is given for both the beer- and water-drinking groups:

a. Name three types of graphs that could be used to examine and compare the frequency distributions of the two samples. Choose one of these methods and construct a graph. What trend is suggested?

b. Test for a difference between the mean changes in mosquito activation between beerdrinking and water-drinking groups.

Transcribed Image Text:

Beer group: 0.36,0.36, 0.46,0.46, 0.06,0.06, 0.18,0.18, 0.25,0.25, 0.18,0.18, -0.06, -0.06,-0.14,-0.14, 0.12,0.12, 0.39,0.39, 0.17.0.17,-0.16,-0.16, -0.05,-0.05, 0.19,0.19, 0.25,0.25, 0.31,0.31, 0.17.0.17,-0.03,-0.03, 0.23,0.23, -0.03,-0.03, 0.26,0.26, 0.30,0.30, 0.11,0.11, 0.13,0.13, 0.210.21 Water group: 0.04,0.04, 0,0, -0.08,-0.08, -0.12,-0.12, 0.201,0.201, -0.039,-0.039, 0.10,0.10, 0.041,0.041, 0.02,0.02, 0.236,0.236, 0.05,0.05, 0.097,0.097, 0.122,0.122, -0.019,-0.019, 0.021,0.021, -0.08,-0.08, -0.165,-0.165,-0.28-0.28